ssize_t rio_readlineb(rio_t *rp,void *usrbuf,size_t maxlen)
{
int n,rc;
char c,*bufp=usrbuf;

for(n=1;n<maxlen;n++){
if((rc=rio_read(rp,&c,1))==1){
*bufp++=c;
if(c=='n')
break;
}else if (rc==0){
if(n==1)
return 0;
else
break;
}else
return -1;
}
*bufp=0;
return n;
}

